eli5: Why does air feel colder when you’re in motion?


eli5: Why does air feel colder when you’re in motion?

In: Physics

Your body heats up a tiny layer of air around your skin. This layer has about the same temperature as your body and the only way you can lose more heat is if this layer is blown away and replaced by colder air. When you move the warmed up air is constantly being replaced by colder air and your body loses heat faster.

Hi! 🙂

Your body gives off energy to the surrounding cooler air.

If you’re stationary, that’s pretty slow. The heat doesn’t just move away quickly. The air next to your skin is warmer than a couple of cm/inches away. It will dissipate, but that’s slow.

If you move, you’re encountering more, still cool air all the time.

More air = more cool 🙂

It’s important to understand how heat is transferred. Hot things are basically particles that are moving fast, and cool things are those moving slow. So heat is basically the speed at which particles move, and they transfer it by numbing into each other. Think of number cars, if one is still and another one is moving fast and bumps into it, the one that is still starts moving and the one that was moving slows down a bit.
Okay so now thinking of your body, air particles hit your skin and your heat is transferred onto them, but they usually stay around the surface area of your skin and slowly spread out. Which means that you lose your heat slowly. Not when there is wind, those particles are now being pushed away from the general area of your skin and your body is transferring heat to new particles, faster. Which means you are losing more heat that you would if they were hanging around your skin.

* You body produces heat inside itself.
* It “feels” cool when that heat leaves your body.
* Normally that heat, heats up the air around you skin.
* But if that warm air is moved away and replaced by cooler air, then you body can release more heat…which feels cool to you.
* So as long as the air moving over your skin is cooler than the heat you’re releasing…you will feel “cool”.

Imagine you took a boiling pot of water and put it on the table and leave it there. After a while, when you remove the pot, the table underneath feels pretty hot.

Now imagine you put the pot on the table, but this time whenever you set it down, you pick it back up again and keep it moving around. If you touch the table after this, no part of the table feels hot at all.

This is because the pot never stayed in one place, and so not much heat was transferred from the pot to the table.

The same logic applies to you when you are moving. When you are still, the air around you heats up to match your body temperature. When you’re moving around, this doesn’t happen, so it feels colder.